FIG. 7 shows vertical cross sectional view of such a conventional centrifugal pump.
As shown in FIG. 7, the conventional centrifugal pump 100 comprises a rotating blade member 102.
This rotating blade member 102 comprises a plurality of impeller members 106, which are radially extended toward the outer periphery, at an upper part of a circular tube bearing portion 104.
In addition, in the specification, the terms that indicate vertical directions, such as “upper side”, “upper portion”, “upper”, “lower side”, “lower portion”, and “lower” indicate the vertical directions in each drawing.
Moreover, they indicate a relative position of each member and they do not indicate absolute positions.
The impeller member 106 includes abase end portion 108 which is extended upward from the bearing portion 104 toward the outer periphery, an enlarged diameter portion 110, of which diameter is enlarged upwardly toward the outer periphery from this base end portion 108, and an outside blade portion 112, which is extended from this enlarged diameter portion 110 toward the outer periphery.
Moreover, as for the rotating blade member 102, a rotor magnet 122, which includes a permanent magnet having an annular shape, is formed on the outer periphery of the base end portion 108.
Between the rotor magnet 122 and the impeller member 106, there is the structure that prevents the turn stop of the rotor magnet 122 and the fall of the rotor magnet 122 against the impeller member 106.
As a result, the impeller member 106 is rotated around an axial member 154 together with the rotor magnet 122.
Furthermore, as shown in FIG. 7, the centrifugal pump 100 includes a main body casing 124 in which the rotating blade member 102 is accommodated.
The main body casing 124 includes an upper main body casing 126.
The upper main body casing 126 comprises a top wall 128 and a side peripheral wall 130 which is downwardly extended from an outer periphery of the top wall 128.
On the side peripheral wall 130 of the upper main body casing 126, a suction side coupling member 132 (sucking side pipe) is fixed in a sealed state.
As a result, the suction side coupling member 132 is connected to the main body casing 124.
Moreover, on the side peripheral wall 130 of the upper main body casing 126, to oppose to the suction side coupling member 132, a discharge side coupling member 136 (discharge side pipe) is fixed in a sealed state.
As a result, the discharge side coupling member 136 is connected to the main body casing 124.
Moreover, as shown in FIG. 7, the main body casing 124 includes a lower main body casing 138 (rotor casing).
Moreover, on an inner wall of a lower end part 141 of the side peripheral wall 130 of the upper main body casing 126, an outer periphery flange 142 of the lower main body casing 138 is fixed in a sealed state.
As a result, in the main body casing 124, an interior space S1, which is surrounded with the upper main body casing 126 and the lower main body casing 138, is formed.
As shown in FIG. 7, this lower main body casing 138 includes a blade accommodating portion 144, which is extended horizontally from an outer periphery flange 142 of the lower main body casing 138 to inner periphery side, and a rotor magnet accommodating portion 146, which is extended downwardly from this blade accommodating portion 144.
In addition, under this rotor magnet accommodating portion 146, a lower bearing member accommodating portion 148, which is of cylindrical shape having a bottom, is formed.
Moreover, in the lower bearing member accommodating portion 148, a lower bearing member 150 is fitted by, for instance, press fit, etc.
In a shaft hole 152 formed in this lower bearing member 150, a lower end portion 156 of an axial member 154 is fixed as pivoted.
Moreover, in the bearing portion 104 of this rotating blade member 102, the axial member 154 passes through so that the rotating blade member 102 can be rotated around the axial member 154.
In addition, the main body casing 124 is provided with a blade casing 158.
This blade casing 158, on the side of the suction side coupling member 132, an outer periphery flange 160 of this blade casing 158 is fixed in a sealed state under the side peripheral wall 130 of the upper main body casing 126.
On the other hand, as for the blade casing 158, an opening portion is formed to the side peripheral wall 162 on the side of the discharge side coupling member 136.
The periphery of the opening portion of this side peripheral wall 162 is fixed to the side peripheral wall 130 of the main body casing 124 in a sealed state together with the discharge side coupling member 136.
Moreover, the blade casing 158 includes a side peripheral wall 162, which is upwardly extended from the outer periphery flange 160, and an extending portion 164, which is extended in the horizontal direction from the side peripheral wall 162 along the outside blade portion 112 of the impeller member 106.
By having such shape, between the blade casing 158 and the blade accommodating portions 144 of the lower main body casing 138, the impeller member 106 can be accommodated.
Moreover, to a protruding portion 128a, which is projected downwardly to a central portion of the top wall 128 of the upper main body casing 126, an upper bearing member 168 is fixed by a fixing holder 161, so that it is protruded downwardly in an inner periphery side opening portion 164a of an extending portion 164 of the blade casing 158.
On a shaft hole 170 formed in the upper bearing member 168, a top portion 172 of the axial member 154 that passes through an inside of the bearing portion 104 of the rotating blade member 102 is fixed as pivoted.
Moreover, by the blade casing 158, the interior space S1, which is formed by the upper main body casing 126 and the lower main body casing 138 is partitioned.
Consequently, a fluid introducing passage 174 is formed in the upper part.
Moreover, a rotating accommodating space S2, in which the rotating blade member 102 is accommodated, is formed in the lower part.
Moreover, as shown in FIG. 7, in the conventional centrifugal pump 100, a coil portion 204 is disposed on the outer periphery of the rotor magnet accommodating portion 146 of the lower main body casing 138 to be located on the periphery of the rotor magnet 122.
In addition, the coil portion 204 which rotates the rotating blade member 102 is provided.
As for the coil portion 204, a plurality of coils 210, which comprise a winding wire 208 rolled in a bobbin casing 206, are disposed in the circumferential direction at predetermined spaces.
In addition, these coils 210, in a coil cover main body 214 having the substantially cylindrical shape, are provided such that they are fitted to the outer periphery of the rotor magnet accommodating portion 146 of the lower main body casing 138 of the main body casing 124.
Moreover, as shown in FIG. 7, a main body casing side fixing bracket 186 is engaged with a coil side fixing protruded portion 216.
Consequently, the coil cover main body 214, in which the coil portion 204 is accommodated, can be provided detachably under the main body casing 124.
In addition, in FIG. 7, the reference numeral 226 indicates a connector, 228 indicates a lead line, and 230 indicates a magnetic pole sensor to detect the direction of the rotation and the position where the rotor magnet 122 is rotated.
In the conventional centrifugal pump 100 configured like this, the electric current flows through the coil 210 of the coil portion 204, so that the coil 210 is excited.
As a result, it effects on the rotor magnet 122 of the rotating blade member 102.
Consequently, the rotating blade member 102 can be rotated around the axial member 154, which passes through the bearing portion 104.
As a result, the fluid sucked from the suction side coupling member 132 passes from the fluid introducing passage 174, which is formed by the blade casing 158 and the upper main body casing 126, to the inner periphery side opening portion 164a of the extending portion 164 of the blade casing 158.
Moreover, the fluid that passes through the inner periphery side opening portion 164a is introduced into the rotating accommodating space S2, which is formed by the blade casing 158 and the lower main body casing 138.
In addition, by the turning force of the impeller member 106 of the rotating blade member 102, the fluid introduced into the rotating accommodating space S2 is discharged through the discharge side coupling member 136 from the rotating accommodating space S2 of the main body casing 124.